I'm having a Navien CR180 tankless hot water system installed soon.I live in southern Ontario where in the winter the water supply temp is around 40F. I'm concerned the unit will not be able to produce water hot enough for a hot shower or running a dishwasher etc.. I'm getting about 2gpm max from any of my taps. I'm not concerned about having enough for 2 operations at the same time like a shower and running the dishwasher as my water pressure is just too low for that. Thanks for any input.